1. Field of the Invention
The present invention relates to an image forming apparatus, an image processing system, a print data output method, and a print data output program product. More particularly, the present invention relates to an image forming apparatus performing image formation on print data, an image processing system including a plurality of image forming apparatuses, a print data output method executed on the image forming apparatus, and a print data output program product.
2. Description of the Related Art
Recently, image forming apparatuses such as printers are generally used in such a manner that they are connected to a network. In this manner, an image forming apparatus is shared by a plurality of users. Therefore, when a user allows a computer connected to a network to transmit print data to an image forming apparatus which is installed at a location distant from the computer, another user can pick up paper having an image formed thereon by the image forming apparatus before the user does. In order to cope with this problem, the image forming apparatus includes a confidential print function that prevents print data from undergoing image formation before a password received with the print data is input. In this confidential print function, the image forming apparatus is allowed to perform image formation in the state in which the user who allows the computer to transmit print data is in the vicinity of the image forming apparatus, thereby preventing paper having an image formed thereon from being examined by other people. In order to allow the image forming apparatus to do printing with this confidential print function set valid, it is necessary to input an instruction into a computer to transmit a password together with print data. Thus, if a user fails to input such an instruction, print data is subjected to image formation even in the absence of the user in the vicinity of the image forming apparatus, and confidentiality thus cannot be preserved.
Japanese Laid-Open Patent Publication No. 6-124177 discloses a scheme of protecting an output of secret print data. In this scheme, an output attribute of transmission print data stored in first storage means and secret condition data set and input beforehand for each user are compared with each other. Print data having an output attribute that does not agree with the secret condition data is allowed to be output by printing means while print data having an output attribute that agrees with the secret condition data is determined as secret print data and then prevented from being output to the printing means. The output attribute of the secret print data and the secret condition are compared with each other according to an input of user password data to display input means, and the secret print data that agrees with the secret condition data is allowed to be output by the printing means. In the output protection scheme disclosed in Japanese Laid-Open Patent Publication No. 6-123177, however, secret condition data has to be set beforehand for each user. Moreover, print data that does not agree with the secret condition data is not protected.
On the other hand, Japanese Laid-Open Patent Publication No. 2001-47700 discloses an image processing apparatus characterized in that an unprocessed job to be processed and a job being processed, which have already been accepted by a control portion, are stored in a removable recording medium when a fatal failure occurs in an image input/output apparatus, and the job stored in the recording medium is read for execution by a control portion of another image input/output apparatus having the recording medium attached thereto by a user. In the image forming apparatus disclosed in Japanese Laid-Open Patent Publication No. 2001-47700, without a fatal failure, a job is executed so that paper is output even when a user is not present in the vicinity of the image input/output device. Accordingly, confidentiality cannot be preserved.